Condensation under Bed?

[suzanne]

I'm planning my conversion.  I am paranoid about condensation/mold so I am educating myself about ventillation and insulation.
Question:   If I put a memory foam mattress on a piece of plywood, and live in the East (where it is humid), am I asking for condensation trouble under the mattress?  Should I design it with air flow under it?  
I'm super excited to finally join this forum...have been compulsively watching van videos for months.  I did a trial 2-week camping run in a Prius and decided that I need to be able to stand up in my home.

 

[user 13531]

Welcome Suzanne!

Totally get the "Stand Up" thing....

 

[Riverman]

Welcome...

 

[B and C]

Welcome!!

I used to get condensation under my mattress. It is laying on plywood that also seperated living space from my "basement"(unheated). The plywood is colder than the inside. You exhale moisture and sweat some too (even if you can't see it). People on boats have the same problem. I bought a mat material (can't remember the name of it to save my life) made for boaters and completely lined the plywood and walls where the mattress touched. This allows any condensation to evaporate as there is airflow between the plywood and mattress. I have read where people drill a bunch (and I mean a bunch) of holes in the plywood for circulation basically turning the plywood into swiss cheese (saves weight too). This assumes that the plywood is entirely within the living space.

 

[Almost There]

Welcome to the CRVL forums Suzanne! Some people have opted to drill holes evenly spaced throughout the plywood bed platform to allow air flow through. Others remediate any moisture by evening out the temperature under their bed. For example, I have my 12V compressor fridge under mine. It provides enough heat that condensation doesn't occur. Others just lift their mattress regularly to allow air flow.

To help you learn the ins and outs of these forums, this "Tips & Tricks" post lists some helpful information to get you started. We look forward to hearing more from you.

 

[suzanne]

Do people use bed slats? Ikea slatted "box springs"? Would be lighter than plywood

 

[deadwood]

You could definitely put some holes in the plywood for extra air circulation. I think lifting the mattress and propping something up under it every so often will help keep it aired out as well. I have a memory foam mattress as well and I do have a very good mattress cover on it that protects it from spills. This also does a great job of keeping moisture out of the mattress.

Air flow and ventilation are so important in such a closed space. So the better your ventilation is the less problems will have a chance to occur. In the end it's not just one solution but a combination of them. Each suggestion so far on this thread is very good but if you can incorporate more to work together you will have a much better chance of success.

 

[Mrcap]

You could definitely put some holes in the plywood for extra air circulation. I think lifting the mattress and propping something up under it every so often will help keep it aired out as well. I have a memory foam mattress as well and I do have a very good mattress cover on it that protects it from spills. This also does a great job of keeping moisture out of the mattress.

Air flow and ventilation are so important in such a closed space. So the better your ventilation is the less problems will have a chance to occur. In the end it's not just one solution but a combination of them. Each suggestion so far on this thread is very good but if you can incorporate more to work together you will have a much better chance of success.

There are other brands out there but this link gives an option.

Aire-flow[emoji769] is designed to prevent moisture build-up underneath mattresses, bunk pads, and cushions. Note: Sold by the Linear Foot

https://www.mattressinsider.com/mattress-condensation-prevention.html


Sent from my iPhone using Tapatalk

 

[B and C]

There are other brands out there but this link gives an option.

Aire-flow[emoji769] is designed to prevent moisture build-up underneath mattresses, bunk pads, and cushions. Note: Sold by the Linear Foot

https://www.mattressinsider.com/mattress-condensation-prevention.html

This ^^ is the exact stuff I use.  Never a problem since installing.  I do make sure that during the day the edges are not blocked by blankets, etc. so it can breath.

 

[bpdchief]

My bed is on 2x4 slats on the metal rails (we call them "hollywood" bed frames) and that seems to allow plenty of circulation. I may still add a USB fan that I can plug into my charge controller to move more air under the bed area - may not, still researching the need. Good luck with your build and travels.

 

[Chuck1]

There is a product called " HyperVent " google that ( im to new to post a link) it allows air underneath a mattress/foam, its used in boats in high humidity environments

 

[suzanne]

Thanks for the ideas!  What about putting a mylar sheet (aka "space blanket" or "emergency blanket"...usually under $4) below products like the "Hypervent" or even under elevated wood slats.  Seems like in the cool weather, it would help retain the heat of my body near the bed without causing condensation.  The order would be:  my body-->mattress--> air space created by Hypervent or wood slats--> Mylar sheet --> plywood or slatted wood base.  Is this overkill?

 

[Almost There]

The order would be:  my body-->mattress--> air space created by Hypervent or wood slats--> Mylar sheet --> plywood or slatted wood base.  Is this overkill?

Yes.

And it would trap any moisture on the mylar that is created. It will pond there.

I sleep in a hammock when canoe/backpacking and used a windproof/waterproof outer protector below my underquilt. In warm weather it works great but when the temperature dropped condensation formed on the topside of the outer protector.

You need to let any moisture created by temp differences go right on through so it can evaporate rather than giving it some place to collect.

 

[Chuck1]

A reflective product like Mylar would work great like you described ( the air gap) that's what its made for.

Below that all you need is the support, i would use a solid sheet of plywood

Ahh the smell of a plan coming together

 

[suzanne]

Yes.

And it would trap any moisture on the mylar that is created. It will pond there.

I sleep in a hammock when canoe/backpacking and used a windproof/waterproof outer protector below my underquilt. In warm weather it works great but when the temperature dropped condensation formed on the topside of the outer protector.

You need to let any moisture created by temp differences go right on through so it can evaporate rather than giving it some place to collect.

Is this why I see people building without painting their plywood?  I thought that unprotected plywood would inevitably absorb moisture  and become moldy in a short time.  I was thinking I need to protect the plywood from moisture.

 

[Chuck1]

The Mylar will be a vapor barrier and protect the plywood, you can seal wood with paint if you want but i wouldn't, water wont pool on the Mylar, on boats with 100% humidity it doesn't, you need to manage your moisture to combat mold growth by venting and or with a moisture absorber (passive or active)

A lot depends on your location, if your on the coast with high humidity then it will be more work, if your mostly in the desert then its not a big problem.

vent vent vent

 

[RollingOm]

I'm planning my conversion.  I am paranoid about condensation/mold so I am educating myself about ventillation and insulation.

Funny story, before I knew anything about condensation I woke up one morning while camping in Mt Shasta, and as I rolled up my foam mattress I saw a huge wet spot on my cot.  "What the heck! I said, did I pee and I didn't even feel it?"  but I felt myself, and it wasn't me  .  The following mornings the same thing happened, so I knew it was some sort of thing related to the weather, or something.  Now that I'm sleeping inside my snugtop with a carpet kit, I haven't had that happen 

RollingOm